IN the early eighties, doctors in the United States were confronted with an outbreak of mysterious diseases most often seen when the immune system is damaged. Soon this trend manifested itself in Western Europe. As the numbers began to dramatically increase, it became clear that a new disease was upon us. AIDS (Acquired Immuno-Deficiency Syndrome) was identified as a new disease in 1981 and the Human Immunodeficiency Virus (HIV) was co-discovered several years later by Luc Montagnier and Robert Gallo and identified as the virus which causes AIDS. It soon became clear that the HIV virus destroys the body’s immune system, i e, its basic defence mechanism, and lays it open for attack by a host of infections.
POSTULATION ABOUT ORIGIN
It has been postulated now for a number of years that the HIV virus originated in Africa some time between the late 1940s and the early 1950s. The earliest known case of AIDS was in a man from the Belgian Congo (now known as the Democratic Republic of Congo) in 1959. His blood, stored since 1959, was recently tested for HIV and found to be positive.
HIV is believed to have evolved from the monkey AIDS virus, SIV (Simian Immunodeficiency Virus). The hypothesis that HIV evolved from SIV is based on the many similarities between these two viruses, especially at the genetic level. These two viruses are genetically very similar, and are transmitted the same way. However, HIV causes AIDS in humans only and SIV causes AIDS in monkeys only. It is now believed that the SIV virus entered human beings from monkeys and, by a yet unknown mechanism, transformed itself into the HIV virus. To date, there have been many theories regarding how monkey blood containing the SIV virus managed to reach the human bloodstream, but all of them have remained inconclusive.
DID A VACCINE CAUSE AIDS?
A recent book, The River: A Journey Back to the Source of HIV and AIDS, by Edward Hooper has resurrected an old controversy regarding the origin of AIDS. Tom Curtis, a journalist, had raised the same issues in the Rolling Stone magazine in 1992. Hooper, a former BBC Africa correspondent and United Nations official, argues in his book that AIDS was accidentally introduced during polio vaccine trials in the 1950s and 1960s.
Hooper’s principal argument in his book is that one or more batches of the vaccine used was contaminated with an AIDS like virus, which came from the monkeys used to produce the vaccine. He contends that the most prevalent form of AIDS — the sort caused by the virus family known as HIV-1 group — was introduced into Africa by way of CHAT, a vaccine against polio. CHAT was developed during the 1950s at the Wistar Institute in Philadelphia by a researcher Hilary Koprowski and then tested on animals in those parts of Congo, Rwanda and Burundi (all then under Belgian rule) where the AIDS epidemic among humans seems to have originated.
It will be noted that in the late 1950s, the Wistar Institute was racing to develop an attenuated live polio vaccine that could be dispensed quickly to protect people from the crippling disease. Koprowski, Plotkin and their Belgian colleagues developed an experimental vaccine in tissue taken from monkeys, tested it in the United States and gave it orally to hundreds of thousands of children during trials.
The two Wistar scientists who led the polio research, former institute director Hilary Koprowski and his former deputy Stanley Plotkin, have rejected the theory raised by the book. For more than a decade, the Wistar Institute and two of its leading scientists have been dogged by speculation that the AIDS virus jumped from chimpanzees to humans through an oral polio vaccine given to more than one million people, mostly children, in central Africa. Now the private, non-profit institute said it would allow two independent labs to test material from the 1957-60 vaccine trials, in the hope that this will end the controversy by showing no evidence of the chimpanzee form of the virus that causes AIDS, called SIV.
UNRAVELLING THE MYSTERY
While the last salvo is yet to be fired in this continuing controversy, many significant issues are at stake. First, the current controversy highlights the problems and difficulties associated with using animal tissue for production of vaccines administered to humans. There may well be other animal viruses that have not yet been discovered that could possibly contaminate vaccine lots.
Second, it points to the manner in which research, which may have unknown consequences, is conducted by using unsuspecting subjects in the third world as guinea pigs. The first widely used polio vaccine was a virulent form of the polio virus that had been killed by formaldehyde. This dead, or inactivated, virus was injected into people to provoke the body’s immune system to manufacture disease-fighting antibodies that would repel the wild, paralysing types of polio. But medical science ultimately rejected this vaccine in favour of a vaccine based on a weakened but still living virus administered by mouth — the oral polio vaccine. Unlike the earlier vaccine, which required periodic booster vaccinations, the oral polio vaccine that confers lifetime immunity, may be taken by mouth and requires no injections.
This vaccine is produced by selecting weakened strains of polio virus and then placing them in tissue cultures — live cells from primates, i e, monkeys, apes or humans. All the polio viruses grown to produce the mass vaccines in the 1950s were fed on a particularly nourishing medium: fresh monkey kidneys. And throughout the 1950s — a period that was barely beyond the dawn of scientific knowledge regarding tissue culture — some of those monkey kidneys were infected with numerous monkey viruses. Scientists knew about some of these viruses, and developed tests to identify and then eliminate the tissues that contained them.
GUINEA PIGS TAKEN FROM THIRD WORLD
Because it was feared that the manufacturing procedure for the new oral polio vaccine almost guaranteed contamination with foreign viruses, initially no country volunteered to be the first to test it. Finally, Belgium volunteered its Central African colonies of Rwanda-Urundi and the Belgian Congo for the trials. It may be recalled that the whole region of Central Africa was under colonial domination, and had no effective voice in international fora.
In any event, in late 1957 in the eastern part of the Belgian Congo, and especially in early 1958 in Rwanda-Urundi, the world’s first mass immunisation campaign using live polio vaccine was carried out. A few months later, the very same batch of vaccine was used again in Leopoldville, capital of the Belgian Congo, 900 miles west of the first campaign. These are today the independent nations of Rwanda, Burundi, and Zaire; and Leopoldville is now known as Kinshasa. Significantly, Rwanda, Burundi, and Zaire — the sites of the first oral polio vaccination campaign — are the three countries which have the world’s highest incidence of AIDS, and all three are in Central Africa where epidemiologists had concluded AIDS had most probably begun. Kinshasa, 900 miles west of the area of the first campaign and given the same batch of vaccine contaminated with an unidentified virus, is today one of the world’s worst struck cities.
Further, the earliest known definitely HIV-positive blood sample yet found anywhere in the world was taken in Kinshasa. The Kinshasa vaccination campaign began in August 1958 and the blood sample was taken in 1959. It is thus possible to map the sites of the first oral polio vaccination campaign carried out by the Wistar Institute, with the areas which currently have the highest incidence of AIDS. The coincidence in time and place is, to say the least, extraordinary.
The theory regarding the polio vaccine having triggered off AIDS, cannot be brushed aside as speculation based on a series of coincidences. There is evidence that transfer of viruses do occur across species as a result of vaccination. In fact, Dr Hilary Koprowski (whose brainchild the African campaign was) himself warned an US Congress committee four years after the trials were conducted, about the dangers of using monkey tissues to grow vaccines. He wrote to the committee saying, “As monkey kidney culture is host to innumerable simian viruses, the number found varying in relation to the amount of work expended to find them, the problem presented to the manufacturer is considerable, if not insuperable.”
SORDID HISTORY OF POLIO VACCINE TRIALS
It may be worth delving into Hilary Koprowski’s antecedents. Koprowski began work for Lederle Laboratories in 1946. Here he took up the cause of saving the world from polio. He tested weakened strains of the polio virus in monkeys and chimpanzees. In March 1951 he revealed that he had become the first physician in history to administer a polio vaccine to humans. The volunteers (subjects of research) for Koprowski’s live, weakened polio vaccine included 20 children whom he later described as mentally deficient; they lived in Letchworth village, a facility operated by the New York State Department of Mental Health. Later he vaccinated other groups of children, among them the newborn babies of institutionalised women in New Jersey. But he was denied permission to conduct larger trials in Belfast (Ireland), amidst reports that his vaccine was not entirely safe. After the Belfast debacle, Koprowski left Lederle Laboratories to direct Philadelphia’s Wistar Institute, then a modest research organisation best known for developing a unique laboratory rat.
Almost immediately, Koprowski arranged to have his weakened polio viruses tested in a colony of 150 chimpanzees in Camp Lindi at Stanleyville, in the Belgian Congo (now Kisangani, Zaire). To protect the animal’s caretakers, these humans too were fed the weakened virus. The successful immunisation of the keepers then became the justification for mass vaccination trials in the Congo itself — the first mass trials in the history of an oral polio vaccine.
Called by drums, rural Africans travelled to village assembly points. There they lined up and had a liquid vaccine squirted into their mouths. Using this spray method, nearly a quarter million Africans were inoculated in six weeks. Later, another 75,000 or so children in Leopoldville, now Kinshasa, also got the vaccine though European children living there apparently received their vaccine in capsule form, possibly a significant variation.
From the beginning, Koprowski’s campaign was marked by controversy. It is reported that Koprowski apparently claimed he had the backing of the World Health Organisation, but the WHO denied sanctioning the mass trial. Koprowski says today that although he was challenged by WHO, he needed only the approval of the Belgian authorities — and there is no doubt he had that.
The Wistar Institute too has been under a cloud on more than one occasion. A few years back, it conducted secret field trials in Argentina on a new rabies virus vaccine. Without bothering to apply for Argentinian government’s approval, Wistar technicians inoculated cattle with a genetically altered recombinant DNA vaccine. According to the Argentinian minister of health, this episode resulted in the infection of up to 17 farm workers. The US government responded by stating that whilst it had funded the Wistar Institute, it had not provided funds for the Argentinian trip!
It is possible that the link between early oral polio vaccine trials and AIDS will never be clinched. But the focus on these trials has shed light on the murky operations that often accompany trials of new vaccines and other remedies. It is hardly a comforting thought that the annals of medical research are strewn with numerous such, little known episodes. As recent experiences in India regarding trials on hormonal contraceptives and anti-fertility vaccines show, medical research continues to be tainted by horrible instances of deliberate malpraxis.